Previous studies have shown that when cats are infected with Brugia malayi and later challenged with an opportunistic streptococcus, 50% of affected limbs become elephantoid. In most instances they return to normal appearance in approximately 18 weeks. We are now studying the effect which reinfection with both Brugia and streptococci with have on recurrence of sequelae and persistence of the elephantoid condition. Similar observations will be made with Sporothrix schenckii. The level of diethylcarbamazine citrate which must be administered to consistently kill adult B. malayi in cats has been established. This information will be used to determine if dead Brugia will form a nidus within a lumphatic vessel causing colonization of streptococci during a transient bacteremia. Patas monkeys currently infected with B. malayi will be monitored to determine the pattern of microfilaremia and to determine if any significant limphatic dysfunction and resulting pathology will occur in chronic infections. At necropsy, the number, condition and distribution of worms will be compared to similar infections in cats. The formation of collateral lymphatic vessels in Brugia-infected limbs of cats will be documented and a search made for lymphatic-venous shunts by using the Microfil technique to study microvascular patterns.